1. Field of the Invention
The present invention relates to rigid, high quality apparatus for covering the rear cargo area of a pick-up type vehicle, commonly known as a tonneau cover, and mounting structure therefor. More particularly, the present invention relates to such an apparatus that is durable, yet lightweight, highly versatile in use, relatively economical to manufacture, easy to install, easy to manipulate for accessing the rear cargo area, and easy to remove if desired. Further, the apparatus is partially generic for use with virtually all makes of pickup trucks, and allows for the use of superior molding technologies for high strength, low weight, and custom shaping.
2. Description of the Relevant Art
Tonneau covers are well known, and are generally either soft, being constructed of a flexible, lightweight material such as canvas, or rigid, being constructed of heavier materials such as fiberglass. Soft covers may be less expensive, but provide no security or load-bearing ability. Rigid tonneau covers are favored for their durability, strength, security, and load-bearing ability, but rigid tonneau covers proposed in the past have several categories of limitations and disadvantages associated therewith.
For example, attachment of existing rigid tonneau covers is complicated. They typically include a maze of hardware for attaching to the vehicle, or they require drilling into the vehicle body. Some use a piano type hinge in the front and gas shocks drilled for support into the vehicle body at the rear. Most open like an alligator mouth, but some do hinge in the middle and open from each side.
Once attached, the conventional rigid tonneau covers, including the various attachment options, limit access to the cargo area and limit the size of what can be carried. In order to take full advantage of the cargo area, one must completely remove the cover. Complete removal of the conventional rigid cover is, however, typically almost as complicated as attachment.
The substantial weight of the conventional rigid cover further complicates removal as well as shipping and storage thereof. Many of these covers weight around 150 pounds or more. Combining the awkward size of most covers and the complicated attachment mechanisms therefor, it is almost impossible for one person alone to remove the cover. Once removed, these covers are difficult to store due to their size and weight. Freight costs related to size and weight of covers restrict the distribution thereof. Large retailers do not carry them because of the high shipping costs and storage difficulties. Many are sold from lots that are outside, usually in a gravel fenced enclosure, which limits public exposure and distribution.
Most of the conventional rigid covers are manufactured from fiberglass, aluminum, or steel. Steel and aluminum covers are easily dented or damaged and are limited in terms of design freedom, so fiberglass is used most often. Fiberglass covers are typically made with an open face mold using resins and fiber cloth either laid in, blown in, or sprayed in with a gun that mixes resin and chops the glass. Since there is little internal strength to a fiberglass resin product, the covers are thick and therefore very heavy. They are also typically molded as a single piece. As a single piece, the cover must be manufactured for a particular model of pickup truck which further adds to the manufacturing cost of conventional rigid tonneau covers and creates additional inventory difficulties.
As a general matter, the conventional fiberglass tonneau covers are quite disadvantageous in terms of durability because there is very limited give between the covers and the truck beds to which they are attached. When the truck bed flexes, twists , bumps, etc. so too does the tonneau cover, and with limited give between the cover and the bed, peripheral edges, connection points, and other stressed portions of the cover become damaged. Further, in conventional designs, when pneumatic or hydraulic cylinders are used to facilitate pivotal lifting of an end of the cover, the cylinders are connected to longitudinally intermediate side portions of the cover, rather than to the non-pivoted end of the cover, for thereby permitting the non-pivoted end of the cover to be raised a relatively large extent. Such intermediate location of the cylinders undesirably places a relatively large load on the cylinders because the distance (lever arm) from the cylinders to the pivot is relatively short, and also place a relatively large load on the portions of the cover to which the cylinders are attached because of the distance from the free end of the cover. Thus it has been conventionally necessary to use cylinders of relatively large capacity, and to significantly reinforce the connecting portions of cover.
Another problem with conventional rigid covers is the quality of appearance. When painted, conventional fiberglass covers in time fade, crack, and show what is called print through where one can see the woven cloth within the fiberglass resin. The underside typically has a rough texture as a result of the fiberglass molding and does not paint well, if painted at all.
Fiberglass covers, due to their paint problems, and aluminum or steel covers, due to their limitations is design freedom, tend to look like an afterthought rather than an integral part of the pickup truck. Appearance problems combined with access limitations, significant weight, attachment and removal problems, and shipping and storage problems, have severely limited the marketability and appeal of known tonneau covers. The following U.S. Patents disclose some specific, conventional tonneau covers.
Dirks, U.S. Design Pat. No. D 398,282 discloses a tonneau cover for a pickup truck bed having two wedge-shaped vertical side members which support a large flat substantially horizontal cover plate, which appears to be pivotally mounted with respect to the side members. Forward of the front edge of the cover plate are two more square auxiliary plates which are disposed side by side and which are smaller than the cover plate.
Friesen et al., U.S. Pat. No. 5,011,214 discloses a tonneau cover made in three panel segments which are pivotally and hingedly joined together, and which are arranged in a side-by-side orientation over the truck bed. The panel segments are connected together by levers and links, somewhat like the components of a convertible top. The hinges between the panel segments run parallel to the longitudinal axis of the vehicle. An actuator may be provided for moving the panel segments between an extended condition with the panel segments arranged side by side and substantially coplanar, and a folded condition with the panel segments arranged face to face at a side edge of the truck bed. Although this design provides the advantages of durability and strength gained from a rigid cover, it is somewhat complex, limits full access to the truck bed, and is difficult to remove.
Swenson et al., U.S. Pat. No. 5,018,777 discloses a hinge and connection assembly kit for a removable truck cap as opposed to a cover. Each hinge connection assembly grasps the channel rail of a box sidewall, by clamping the truck rail with a tightenable threaded damping plate, and includes a hinge mounting bolt. The head of the hinge mounting bolt rests against the truck box side wall. This design provides the feature of easy removeability, but is designed for use with truck cap or camper shell rather than a tonneau cover. Such a design yields a cap that is typically heavy and awkward to open or remove. It also limits access to the truck bed without full removal.
Wheatley, U.S. Pat. No. 5,121,960 discloses a rail attachment system for a flexible truck tonneau cover. The rail attachment system of Wheatley includes a pair of matching clamping members which clamps a rail to a truck bed side wall without drilling holes therein. A nut and bolt clamp the two clamping members together against the truck wall section. Although easy to remove, this design is limited to a flexible tonneau cover and does not provide the advantages of a rigid tonneau cover such as durability, strength, and load bearing characteristics.
Jordan, U.S. Pat. No. 5,183,309 discloses a rigid, low profile tonneau cover for a truck. The tonneau cover of Jordan is made in three sections which are hingedly and pivotally joined together. As in the Friesen reference, the hinges between the panel segments run parallel to the longitudinal axis of the vehicle. A framework is provided below and supporting the center section, and the side panels are attached to the center section using gas shocks, so they can be pivotally lifted upwardly for access to the contents of the truck bed. Although providing easy access, this design limits access to the truck bed, and is difficult to mount as well as to remove.
Isler, U.S. Pat. No. 5,322,336 discloses a hinged tonneau cover for a pickup truck. The tonneau cover of Isler is a framework covered by a soft top, which is attached to the front of the truck bed with a hinge connection, and which is attached at the back by a pair of gas shocks. Specially modified C clamps are provided to connect the base of each gas shock to the truck bed, and the C clamps mount onto the truck side wall without requiring drilling holes thereinto. Although easy to attach and remove, this design is limited to a flexible tonneau cover and does not provide the advantages of a rigid tonneau cover such as durability, strength, and load bearing characteristics.